lix/src/nix-instantiate/help.txt

nix-instantiate [OPTIONS...] [FILES...]

`nix-instantiate' turns Nix expressions into store derivations. 

The argument `-' may be specified to read a Nix expression from
standard input.

Options:

  --version: output version information
  --help: display help

  --verbose / -v: verbose operation (may be repeated)

  --eval-only: evaluate and print resulting term; do not instantiate
  --parse-only: parse and print abstract syntax tree

  --add-root: add garbage collector roots for the result
* Help text for all (non-script) programs, so no more: $ nix-instantiate --help error: unknown flag `--help` Try `nix-instantiate --help' for more information. :-) 2003-12-01 15:55:05 +00:00			`nix-instantiate [OPTIONS...] [FILES...]`

* nix-store, nix-instantiate: added an option `--add-root' to immediately add the result as a permanent GC root. This is the only way to prevent a race with the garbage collector. For instance, the old style ln -s $(nix-store -r $(nix-instantiate foo.nix)) \ /nix/var/nix/gcroots/result has two time windows in which the garbage collector can interfere (by GC'ing the derivation and the output, respectively). On the other hand, nix-store --add-root /nix/var/nix/gcroots/result -r \ $(nix-instantiate --add-root /nix/var/nix/gcroots/drv \ foo.nix) is safe. * nix-build: use `--add-root' to prevent GC races. 2005-02-01 12:36:25 +00:00			`nix-instantiate' turns Nix expressions into store derivations.
* Help text for all (non-script) programs, so no more: $ nix-instantiate --help error: unknown flag `--help` Try `nix-instantiate --help' for more information. :-) 2003-12-01 15:55:05 +00:00
			The argument `-' may be specified to read a Nix expression from
			`standard input.`

			`Options:`

			`--version: output version information`
			`--help: display help`

			`--verbose / -v: verbose operation (may be repeated)`
* Document --eval-only and --parse-only options in nix-instantiate. 2004-11-12 23:22:08 +00:00
			`--eval-only: evaluate and print resulting term; do not instantiate`
			`--parse-only: parse and print abstract syntax tree`
* nix-store, nix-instantiate: added an option `--add-root' to immediately add the result as a permanent GC root. This is the only way to prevent a race with the garbage collector. For instance, the old style ln -s $(nix-store -r $(nix-instantiate foo.nix)) \ /nix/var/nix/gcroots/result has two time windows in which the garbage collector can interfere (by GC'ing the derivation and the output, respectively). On the other hand, nix-store --add-root /nix/var/nix/gcroots/result -r \ $(nix-instantiate --add-root /nix/var/nix/gcroots/drv \ foo.nix) is safe. * nix-build: use `--add-root' to prevent GC races. 2005-02-01 12:36:25 +00:00
			`--add-root: add garbage collector roots for the result`